#include <iostream>

template <typename T>
class Base
{
public:
    T a;
    int b;
};

class Child : public Base<int>
{
};

template <typename R>
class Child2 : public Base<int>
{
public:
    R r;
};

int main(int argc, char const *argv[])
{
    

    Child2<int> child{};

    child.r = 123;
    child.b = 123; // 如果在继承的时候没有找到template 类型，则就会报错

    return 0;
}
